Improvement in steam-engine valves



NITED STATES "PATENT F l HGRAGE l n. woons, or ROCK ISLAND, ILLINOIS.

IMPROVEMENT IN STEAM-ENGlNE VALVES.

Specification forming part of'Letters Patent No. l92,04 1, dated June 12,1877; application filed May 10, 1877.

To all whom it mag concern: i

Be it known that I, HORACE E. WOODS, of Rock Island, in the county of Rock Island and State of Illinois, have invented certain new and useful Improvements in Steam-Engines, of which the following is a' specification:

This invention relates to certain improvements in the construction of steam-engines; its object being to provide for using the steam expansively, and at the same time provide for the rapid discharge of the waste steam bymeans of peculiarlyconstructed steam-ports.

My invention consists, essentially, of a valve-chest having a central induction-port,

and surrounding annular chambers at each end, and constructed with the trapezoidalshaped ports communicating with the cylinder of the engine and with one of said annular chambers at each end of the valve-chest,

7 chest, with a portion of the outer shell of the latter broken away, showing the ports of said water-chest.

The letter A represents the engine cylinder, and B the piston of the same. 0 O represent the ports leading to each end of said -cylinder, said ports communicating, respectively, with two annular chambers, D D, surrounding the valve-che'stE, near eachend, by

means of the peculiarly-shaped ports F F. The said ports are constructed in the shape of trapezoid, with the bases or enlarged portions toward the opposite ends of the valvechest and the constructed portions toward the center of said valve-chest. The letters G G represent two annular chambers surrounding the valve-chest at its ends, and communicating with said valve-chest by means of the ports H H, and with the eduction-ports atI I. The

' letter K represents a hollowvalve-stem, connecting the two pistons L and L, which move in the valve-chest, and serve to control the induction and eduction of the steam to and from the ends of the cylinder alternately. resents the induction-port, which enters the valve-chest between the two pistons of the valves.

The valve-chamber and steam-cylinder are preferably cast in one piece, although they may be separately formed and secured together in any convenient manner, if desired.

The operationof my invention is as follows: In Fig. 1 the piston of the engine is repre- -sented at its half-stroke, in which the ports F F. are both entirely uncovered by the pistons, the port F being in full communication with the port() leading to the cylinder A, and

I connecting said port with the exhaust-port of the valvechest. The port F is, at the same time, in. fullconnection with the port 0, connecting it with the central portion of the valvechest, and supplying steam to the cylinder. As the piston continues its stroke the piston L gradually moves toward the smaller or contracted portions of the ports F, while the piston L will, at the same time, move toward the passed the ports F and F, leaving the smaller ends of the ports F, in connection with the central portion of the steam-chest, in position to commence to admit steam from the chest to the cylinder, and the larger ends of the ports F in position to commence exhausting from the cylinder. The piston-valve will still continue its motion in the same direction,

gradually opening the ports F froin theirsmaller to their largerends, and gradually opening the ports F from their larger to their smaller ends, until the ports F and F are again fully closed, when the piston of the engine will be again on the half-strokein the' direction opposite to that shown in Fig. 1, when the engine will commence to work in a manner similar to that first described.

It will thus be perceived that the inductionports of the engine, during the greater portion of its operation, are smaller in area than the eduction-ports, by which I am enabled to hold the steam in the cylinder in order to work it expansively, and at the same time provide for the free and rapid eduction of the discharge steam.

What I claim, and desire to secure by Letters Patent, is v The valve-chest E, having an inductionport, and the surrounding annular-chambers D D and G G at its ends, and constructed with the trapezoidal ports F, communicating with the cylinder of the engine and the chambers D D, and the ports H H, communicating with chambers G G, and eduction-ports I I, in combination with the hollow valve-stem K, having at its ends the pistons L L, substantially as and for the purpose described.

In testimony that I claim the foregoing I have hereunto set my hand in the presence of the subscribing witnesses.

,YHORAUE E. WOODS.

Witnesses:

JOHN THOMPSON, CHRISTIAN SGHILLING-ER. 

